Aliskiren, (2S, 4S, 5S, 7S)-N-(2-carbamoyl-2-methylpropyl)-5-amino-4-hydroxy-2,7-diisopropyl-8-[4-methoxy-3-(3-methoxypropoxy)phenyl] octanamide having the Formula-I, a new antihypertensive has been developed which interferes with the renin-angiotensin system at the beginning of angiotensin II biosynthesis.

Aliskiren is marketed by Novartis as TEKTURNA® in the form of its hemifumarate salt in a once-daily formulation.
U.S. Pat. No. 5,559,111 discloses Aliskiren and related compounds along with the synthesis of Aliskiren.
Further U.S. Pat. No. 7,132,569, U.S. Pat. No. 7,009,078, U.S. Pat. No. 6,730,798 and U.S. Pat. No. 6,800,769 claims novel intermediates used in the preparation of Aliskiren and process for the preparation of Aliskiren, which are incorporated here for reference. U.S. Pat. No. 7,132,569 discloses compound of Formula-II, which is used as an intermediate in the preparation of Aliskiren and process for the preparation of the same.

In this patent the obtained compound of Formula-II is purified by flash chromatography.
As the Aliskiren comprises, 4 chiral carbon atoms, the synthesis of the enantiomerically pure compound is quite demanding. The intermediate of Formula-II is commercially important in the synthesis of Aliskiren as well purity of the said intermediate play a vital role to achieve pure Aliskiren. Therefore an improved process for the said intermediate is needed to obtain pure intermediate which helps to obtain pure Aliskiren.
Thus the present invention provides an improved process for the preparation of Aliskiren intermediates and further conversion into Aliskiren.